Synchronizing and regulating mechanism for combination steam and explosion engines



C. T. LITCHFIELD.

SYNCHRONIZING AND REGULATING MECHANISM FOR COMBINATION STEAM AND EXPLOSION ENGINES.

APPLICATION HLED FEB. 5. 19H].

Patented Aug. E [T8 17, 1920. 2 SH SHEET 1.

TTORNE Y CL UTCH GOV- N R C. T. LITCHFIELD. SYNCHRONIZING AND REGULATING MECHANISM FOR COMBINATION STEAM AND EXPLOSION ENGINES.

APPLICATION FILED rm. 5. 191B.

'1 ,349,6 1 9 Patented Aug. 17, 1920.

2 SHEETS-SHEET 2.

.47 F f 2 294. R I N g?- i 5 IN VENTOR. Uczrks BY 5 Z/% We]; NE YS.

UNITED STATES PATENT OFFICE.

CHARLES T. LI'ICHFIELD, 0F SPOKANE, WASHINGTON, ASSIGNOI-t 'I'O WILLIAM B. GERARD AND GEORGE C. JACKMAN, BOTH OF SPOKANE, WASHINGTON.

SYNCHRONIZING AND REGULATING- MECHANISM FOR COMBINATION STEAM AND EXPLOSION ENGINES.

Specification of Letters Patent.

Patented Aug. 17, 1920.

Application filed'lebruary 5, 1918. Serial No. 215,503.

To all whom it may concern:

Be it known that I, CHARLES T. LITCH- FIELD, a citizen of the United States, resid ing at Spokane, in the county of Spokane and State of lVashington, have invented new and useful Improvements in Synchronizing and Regulating Mechanism for Combination Steam and Explosion Engines, of which the following is a specification.

This invention relates to that type of mo tive power units which involve the combination of a steam engine, a steam boiler, and an explosive engine for generating steam in said boiler to operate the steam engine, power being taken from both engines.

In this type of power unit, my invention has for one of its objects the provision of means for synchronizing the application of driving thrust of one type of engine with respect to the other, on a vehicle or other shaft which is common to the two engines. This synchronization of the application of driving thrust,-which I consider novel alone, is used in combination with means for synchronizing the speed of the two engines, which latter feature I consider novel in itself, and also novel in combination with the thrust synchronizing feature.

A further feature of my invention 'consists in governing the supply of steam from the boiler to the steam engine in such a manner that the steam engine will be automatically shut off 'when pressure falls, below a predetermined minimum, and willbe automatically started when pressure rises up to such minimum. This feature of my invention is embodied in an engine pressure regulator which automatically operates as the pressure in the boiler varies.

My invention also includes novel means, acting in an auxiliary capacity or relation with respect to the explosion engine, as a heater, in order to maintain boiler pressure as nearly constant as possible.

-My invention has other objects and features which will be more fully described in the following specification, and which will be more particularly pointed out in and by the appended claim In the drawings:

Flgure 1, is a sectional View on line 11 of Fig. 2.

Fig. 2, is a plan view of the structure shown 111 Fig. 1, also including portions of the engines.

Fig. 3, is a sectional view of the engine pressure regulator on line 3-3 of Fig. 2.

Fig. 4c, is a sectional view on line 44; of Fig. 2.

Like characters of reference designate similar parts throughout the different figures of the drawings. 9

Referring to the specific form as shown in the accompanying drawings, 1 designates one of the cylinders of a steam engine, and 2 designates one of the cylinders of an exploslon engine, there being of course more than one cylinder for each engine. A boiler 18 generally designated at 3, and the boiler will be in such relation, and will be connected up with the explosion engine in such a manner that the latter will generate steam in the boiler for the purpose of operating the steam engine. The detailed construction of the boiler, and the specific manner in which the explosion engine heats the boiler to generate steam therein, need not herein be specifically disclosed because of the fact that this broad combination only is important in connection with the remaining' features of the case which will now be described in detail.

A pipe 4 leads from the boiler 3 to deliver steam to the steam engine, and interposed in said pipe is a novel form of engine pressure regulator and cut-off, the latter being broadly designated at 5 and being shown in detail in Fig. 2.

The pipe 4: has an initial cut-01f valve seat 5 with which an initial cut-off valve closure 6 coacts. Closure 6 has a stem 7 which is suitably guided by socket 8, formed in the casing of the valve structure. The stem 7 is provided with teeth 9 which are adapted to mesh with the teeth 10 of a crank 11. Crank 11 is pivoted at 12 so that linear movement of the valve stem 7 will oscillate the crank 11 dependent upon the direction of movement of stem 7. The remaining end of crank 11 is bifurcated at 13 to straddle the stem 11 of a differential retainer valve means. The bifurcated end is also forked, as indicated at 15, to engage a pin 16, the latter being mounted on stem 11. It will therefore be seen that the foregoing means provides for positive transmission from stem 14. to stem 7, and vice versa, with an ample leverage favoring the stem 14. .T he differential piston means includes the relatively small surface piston 17, guided in a socket 18, and having a relatively small surface 19, exposed to steam pressure. This differential retaining means also includes a piston 20, fixed on the other end of the stem H, and guided in socket 21, and having a relatively larger diiferential surface 22, exposed to steam pressure. The said retaining means is normally actuated by a spring 23, for maintaining the initial shut-off closure seated, as shown.

The parts are so arranged, adjusted and proportioned that when pressure in the boiler reaches 600 lbs, for instance, this pressure will open closure 6, against the action of spring 23. Once opened, the pressure on 22, will overcome the spring and the lesser pressure on 19, and hold the closure 6, open, until pressure drops below 100 lbs, whereupon, the spring 23, combined with the pressure on 19, will shift the retaining means back to the closed position shown.

Steam flows down passage 24 between balanced puppet 25 and piston 26, both fixed on rod 28, their facing surfaces being of equal area. Rod 28 also carries piston 31, sliding in socket 33. A spring 34, engaging piston 31, normally acts to shift the pistons and puppet to the right and unseat the puppet to open flow for the steam into passa e 29, and therefrom to the steam engine. liston 31 has a face 32 of sufficient area to overcome spring 34 and close the puppet 25, when pres sure in passage 29 rises above 400 lbs. but just as soon as pressure drops below 400 lbs, the spring 34, will shift the pistons and open puppet 25.

It will thus be seen that the initial shutoff and the differential retaining means control admission of steam to the regulator or nniformer within predetermined ranges, which, as set forth as an example, are a maximum of 600 lbs. and a minimum of 400 lbs. It will also be understood that the pistons 26 and 31, and the puppet 25, constitute uniform admission means whereby the engine will always be supplied with steam at substantially 400' lbs. pressure irrespective of the variation of pressure within the maximum and minimum that may occur in )assage 24.

ll hen this pressure admission and regulator valve structure is combined with means, hereinafter described, for supplying a practically constant and uniform heat to the boiler, or in other Words, ap )lying heat such that the steam pressure wil l be nearly uniform, that I have devised a most efficient mechanism for generating and supplying steam with a view of securing admission to the engine as nearly uniformly as possible.

It will thus be seen that irrespective of the variation of pressure in the boiler, between the maximum and minimum pres sures, the engine will always be supplied with constant pressure of steam, and further when the pressure falls below the minimum, the engine is cut-off and when the pressure again rises, the engine is automaticall started.

lowever, inasmuch as reliance is placed partly on the explosion engine to heat the boiler, and inasmuch as the explosion engine may be running at a slow speed, or if for any other reason the heat of the explosion engine fell below the necessary requirements to keep up steam in the boiler, boiler pressure would necessarily lower beyond a point which would be necessary in order to operate the steam engine. In this event the power unit would be rendered inoperative. Inasmuch as it is one of the principal objects of this invention to apply this power unit to a motor driven vehicle, the necessity for auxiliary heating means will be quite apparent, especially in the matter of starting.

Now therefore it is a very important feature of this invention to provide auxiliary heating means whereby the deficit of heat resulting from the explosion engine running slow or being stopped, can be made up. in order to maintain a head of steam in the boiler substantially constant.

I have shown one means of performing this function which I will now describe in detail.

interposed in pipe 4 is a main shut-off valve 36 which will be manually operated, in any desirable manner. A hydro carbon burner 37, or a pl-uralitive thereof, will be disposed below the boiler. A tank 38 will be provided for the liquid fuel and under suitable pressure, the fuel will flow through pipe 39 to burner 37. Interposed in pipe 39 is a valve 40 having a valve arm 41. Valve arm 41 is pivoted at 42, slidably to ajpiston rod 43 on which is disposed a-piston 44?. Piston 44 is slidable in a cylinder 45 which opens to pipe 4 through a pipe 46 and is therefore exposed to steam pressure in advance of the regulator 5. On the other side of piston is a spring 4L7.

The arrangement is such that when pressure in the boiler goes down, the spring 47 will move piston 44 toward pipe 4 and open valve 40 to increase the flame of burner 37. When pressure increases, piston 44 will be moved in a reverse direction tending to close, but not closing valve 40. Thus as the heat from the explosion engine decreases the burner flame will increase, and vice versa, with a view of automatically providing a substantiall constant boiler pressure. The valve 40 will be arranged, or of such a construction that it will never completely close thereby providing at all times a small pilot flame which will prevent freezing, and which will otherwise maintain the boiler warm.

It will be seen that when the main shutoff valve 36 is completely closed, that in the absence of some special provision the pressure in pipe 4 would decrease so that spring 47 would open valve 40 and increase the flame of burner 37. Therefore I provide means in the form of an arm 47 on the operating member 48, of valve 36, so that when valve 36 is closed, the arm 47 will engage an abutment 49 and force arm 41 into a position to nearly close valve 40, or leave said valve open enough to supply the pilot flame.

Attention will next be directed to means for synchronizing the application of driving thrust of one engine with respect to the other.

As shown, 50 designates the crank shaft of the explosion engine. A clutch 51, of any approved type, positively connects the explosion engine shaft with a shaft 52, which I will term the vehicle shaft, because when my invention is applied to a motor, driven vehicle, shaft 52 will be the drive shaft. In any event this shaft 52 will be one which is common to the shafts of the two engines. The steam engine shaft is designated at 53. At this point, it may be stated that the clutch 51 may be employed to throw out the explosion engine.

On steam engine shaft 53 is mounted a gear wheel 54 which meshes with an intermediate idler gear pinion 55. Idler 55 meshes with a gear pinion 56. A frame 57 is generally indicated and is provided with bearings 58, 59, and 60, the purpose of which will be obvious. Gear pinion 56 is loose on shaft 52 but is fixed on a clutch casing 57. This clutch casing 57 is also loose on shaft 52. A clutch disk 61 is fixed on shaft 52 and is disposed in said casing 57. Casing 57 is provided with one or more socket enlargements 62, shown more particularly in Fig. l. A wedge clutch member 63 is interposed between the periphery of disk 61 and the inner wall 64, of said enlargement. This clutch member has an arcuate face 65 for engagement with the periphery of disk 61. It will be noted that the radio cross section of the clutch member 63 is greater at a, than at b.

A spring 66 normally acts to shift the wedge member 63 into locking engagement against the periphery of disk 61 and the lockingwall 64.

It will now be clear, assuming that drive of both engines is in the direction indicated by the arrows shown in Fig. 1, it will be seen that disk 61 is driven by the explosion engine whereas casing 57 is driven by the steam engine. If both engines are running at precisely the same speed, meaning of course the same relative speed in view of the gearings ratio, then, driving thrust of both engines would be imparted with equal force to shaft 52. If the explosion engine attains a greater relative speed then the clutch member 63 is moved to the left and frees the steam engine thereby permitting the same to run at a slower relative speed than the explosion engine. If however the explosion engine is running slower, relatively, than the steam engine, the wall 64, of the casing 57 will wedge on one side of member 63 and disk 61 will tighten up on the other side, and the explosion engine will be advanced in speed until it equals the speed ratio with respect to the steam engine.

The foregoing device thereby serves to synchronize the application of thrust of one engine with respect to the other. I will now describe the means for synchronizing the speed of the two engines.

Any suitable form of governor, such as a marine governor, generally indicated at 67, is operatively associated so as to be driven by shaft It is not necessary to specifically illustrate any particular form of governor since my invention only includes the governor broadly. The governor 67 is operatively connected with a rod 68 which is pivoted to a crank 69 on a throttle valve shaft 70. Throttle shaft 70 operates throttle valve 71, in passage 29, Fig. 3, and when the steam engine speeds down below the relative speed with respect to the explosion engine, then governor 67 opens the throttle to speed up the steam engine. Therefore it will be seen that, specifically considered, the explosion engine governs the speed of the steam engine. However, broadly considered, a foundation is provided for claimin means for synchronizing the relative speed of exlosion and steam engines. For instance, should the steam engine speed up so as to drag the explosion engine along, then the governor 67 would act to close the throttle and reduce the speed of the steam engine. It will be understood that a governor will be employed which is very highly and sensitively responsive to the slightest variation of speed of the shaft 52 and therefore at the instant when the steam engine attempts to drag the explosion engine the throttle 71 will be instantly closed down.

It is believed that the advantages and utility of my invention will be clearly understood from the foregoing description and while I have herein shown and described one specific form of my invention, I do not wish to be limited thereto except for such limitations as the claims may import.

I claim:

1. The combination. with a steam and an explosion engine, of a vehicle shaft in positive driven relation with said explosion engine, characterized by mechanism for coupling the steam engine with said shaft when the steam engine is running at the same or at a greater speed than the explosion engine and releasing said steam engine when the latter slows down With respect to the explosion engine, and a governor means operated by said shaft for synchronizing the speeds of said steam and explosion engines.

2. The combination with a steam and an explosion engine, of a vehicle drive shaft in positive driven relation with said explosion engine, characterized by means for coupling said steam engine with said shaft when the steam engine is running at the same or at a greater speed ratio than the explosion engine, and means operatively c011- nected with said shaft for increasing the speed of the steam engine up to the ratio speed of the explosion engine.

3. In combination, a steam engine, a steam boiler for operating said engine, a main shut-off valve for cutting off steam from said boiler to said steam engine. an explosion engine for generating steam in said boiler, a burner for applying heat to said boiler, a fuel valve device for controlling admission of fuel to said burner to increase or reduce the flame or reduce the flame to a pilot, a steam pressure actuated means be tween said steam engine and said main valve for opening or closing said fuel valve as the heat from said explosion engine varies, and means actuated upon closing movement of said main valve for imparting closing movement to said fuel valve irrespective of the action of said pressure actuated means.

4. The combination with a steam and an explosion engine, of a drive shaft connected for direct drive by said explosion engine, means for connecting said steam engine into drive with said shaft, and means energized by said drive shaft for synchronizing the speed of said steam engine with said explosion engine.

5. The combination with a steam and an explosion engine, of a shaft driven by said explosion engine. means for connecting said steam engine into drive with said shaft, and means operatively connected with said shaft for throttling said steam engine to synchronize the speed of the latter with the speed of said explosion engine.

6. The combination with a steam and an explosion engine with a throttle valve for the former, of a shaft driven by said explosion engine, means connecting said steam engine into drive with said shaft, and a overnor operated by said shaft for control ing the throttle valveof said steam engine.

7. The combination with a steam and an explosion engine, a shaft driven by said explosion engine and having a clutch member, a companion clutch member driven by said steam engine, an actuated clutch element operatively connecting said clutch members to transmit drive from said steam engine to said shaft, and means energized by said shaft for synchronizing the speed of said stea'm engine With said explosion engine.

In testimony that I claim the foregoing as my own I hereby afiix my signature.

CHARLES T. LITCHFIELD. 

